The present invention relates to socket tools. More precisely, the present invention relates to self-forming sockets that adjust to nuts and bolt heads of different sizes and shapes.
Many of today's machines are assembled using bolts, nuts, wing-nuts, screws, and similar fasteners. In order to work with such fasteners, wrenches and socket sets are often needed. Unfortunately, there is a large variety of such fasteners. Even for a standard hex-head bolt, there are numerous English and metric sizes. For a craftsman to be fully prepared to work with such a myriad of bolts, he must maintain a large assortment of socket sizes, and sometimes that assortment must include different socket shapes. Having to locate the correct size socket-head and switching between different sized socket-heads to use in conjunction with a wrench or power tool are cumbersome and inconvenient tasks.
As a result, there have been developments into sockets that self-adjust to the particular size and shape of the bolt head or nut. For example, U.S. Pat. No. 3,858,468 to Pasbrig et al. discloses a clamping tool having a housing with a chamber therein and an opening at one end. A plurality of bundled, square shape bars are disposed in the chamber, wherein the bars are individually displaceable inward of the housing against the spring action of a pad. As the tool is pushed over the head of a bolt or a nut, the bars in contact retract into the pad and surrounding the nut or bolt head thereby gripping the part. The bolt head or nut can then be torqued as necessary. U.S. Pat. No. 3,698,267 to Denney discloses fastener actuator having a plurality of fastener engaging elements, wherein the elements are bundled and slide independently and longitudinally into and out of the actuator to accommodate a bolt head, nut, or slotted screw-head. Each element has a rectangular cross-section in order to grip the flat sides of a standard bolt head, or to fit into the flat walls of a slotted screw-head.
U.S. Pat. No. 4,887,498 to Zayat discloses a tool for form engaging and turning components such as nuts, bolts, and screws. In its basic form, the Zayat device includes a chamber which in turn supports a bundle of pins each of which is adapted to slide farther upwardly into the chamber when the lower pin end contacts the component at the lower end of the housing. Each of the pins has flat sides and sharp corners in order to engage a nut either by the flat sides or the sharp corners.
U.S. Pat. No. 3,349,655 to Locke discloses an adjustable tool for installing or removing fasteners of various sizes, comprising of a bundle of rods surrounded by a girdle and resiliently mounted in a chuck. The rods may be pressed into conformity with the head of a fastener, and upon the application of torque to the chuck, the girdle constricts and accordingly torque is applied to the fastener through the rods. Each of the rods has flat sides and the rods of the bundle are tightly packed.
U.S. Pat. No. 1,529,605 to Muncey discloses a wrench having closely packed and individually extendable rods that engage a bolt head or nut. Each of the extendable pins has a rectangular shaped cross-section.
The foregoing teach methods of gripping a three dimensional object by using polygonal shape pins closely packed in parallel in a bundle and independently displaceable longitudinally to accommodate the height dimension and contours of the device to be gripped. This construction has been used in a vise as well, as disclosed in U.S. Pat. No. 2,754,708 to Peterson.
There have been other attempts at self-adjusting sockets. For instance, U.S. Pat. No. 5,157,995 to Nogues discloses a multiple socket wrench comprised of several coaxially disposed socket members housed within each other. The sockets are spring loaded and each has a reduced diameter towards the outer end that prevents the abutting sockets contained therein from falling off as a result of gravity or the spring force of the different spring members associated with each one of the sockets. Each spring urges each socket outwardly, and the springs of the sockets that are smaller than the head of the bolt or screw being matched are overcome and retracted, thereby automatically matching the correct size socket to the head of the bolt or nut. Additionally, U.S. Pat. No. 2,711,112 to Durand discloses another multiple socket wrench having coaxially aligned sockets of varying sizes organized on the ratchet in a concentric arrangement.
U.S. Pat. No. 5,193,420 to Smith is directed to a universal wrench for use with vehicle lug nuts. A two piece housing containing a plurality of spring-biased retractable round pins is shown. The pins are spaced apart from each other to allow assembly of the tool and to allow placement of adaptor cones on the end of each pin. These round pins appear to function independently of each other since the pin distal ends are spaced from any further components in a non-contacting arrangement. Hence, the pins must transmit torque to a fastener by bending forces along their length. The pins cannot be closely packed since the pin head 25 is of a second diameter greater than a first diameter of the engaging pin 24, which is the portion which engages a fastener. The pin heads 25 must further be spaced from each other to be contained within the first housing 11.
In view of the foregoing, however, there is still a need for a self-forming socket that self-adjusts and form fits to various sizes and shapes of bolt heads, nuts, screws, etc. with a hexagonal overall shape and without harmful sharp cornered pins.